Stack-memory disclosure via uninitialized CAN BCM padding
Published Jun 14, 2021 · Updated Aug 4, 2024
Information disclosure in Linux kernel 2.6.25 through 5.12.10 allows local users to read kernel stack memory through CAN BCM messages. On 64-bit systems, four padding bytes between count and ival1 in struct bcm_msg_head remain uninitialized when bcm_read copies the structure to user space. A local user must be able to create and read a CAN BCM socket, and the exposed bytes can contain sensitive data left on the kernel stack.
Summary
What happened
Information disclosure in Linux kernel 2.6.25 through 5.12.10 allows local users to read kernel stack memory through CAN BCM messages. On 64-bit systems, four padding bytes between count and ival1 in struct bcm_msg_head remain uninitialized when bcm_read copies the structure to user space. A local user must be able to create and read a CAN BCM socket, and the exposed bytes can contain sensitive data left on the kernel stack.
The record
- CVE
- CVE-2021-34693
- Published
- Jun 14, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-909, T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 14, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- kernel-exploitation CVE-2021-34693 poc.cproof of concept · unverified
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Technologies
Your stack
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Your stack
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